Expression of α-SMA was significantly increased in cardiac muscle of BO mice (Control (n = 5) vs. BO (n = 4); 1.0 ± 0.4 vs. 2.5 ± 0.9 arbitrary unit (A.U.), P < 0.05 vs. Control), and the increase was significantly suppressed by vidarabine (BO (n = 4) vs. BO + vidarabine (n = 4); 2.5 ± 0.9 vs. 0.7 ± 0.5 A.U., P < 0.01 vs. BO) (Fig. 2c). Here, ACTA1 is linked to bronchiolitis obliterans syndrome.